Modern aircraft are often propelled by sets of turbofan engines that provide thrust for the aircraft. Such turbofan engines are typically arranged on opposing sides of a fuselage under (or sometimes over) wings that extend from the fuselage. The turbofan engines are mounted to a structural frame of the aircraft so that thrust provided by the turbofan engines moves the entire aircraft.
Each turbofan engine includes a fan that rotates to push air and propel the aircraft. The rotation of each fan creates a torque that is applied to the frame of the aircraft during operation of the turbofan engines. Generally, the fans of the turbofan engines rotate in the same direction which induces torque in the same direction and requires the frame of the aircraft to react the torque of each fan.